Cellular Structure and Functions
Biomolecules
PROTEIN AND DNA
PROTEIN STRUCTURE
The quaternary structure of a protein is the association of several protein chains or subunits into a closely packed arrangement.
the association of several protein chains or subunits into a closely packed arrangement
The tertiary structure of a protein refers to the overall three-dimensional arrangement of its polypeptide chain in space.
Three dimensional arrangement of
its polypeptide chain
Hydrogen bonds between sections of the protein chain are responsible for the secondary structure of the protein
The sequence of amino acids linked together to form a polypeptide chain. Each amino acid is linked to the next amino acid through peptide bonds created during the protein biosynthesis process.
amino acids are linked together by peptide bonds, thereby forming a long chain
The primary structure of protein
forms an amino acid chain.
The amino acids are stabilized by
Hydrogen bonds
These hydrogen bonds
create alpha helix and beta pleated
sheets for the secondary structure
PROTEIN FUNCTION
receive signals from outside the cell and mobilize intracellular response
Signals most often move through the cell by passing from protein to protein, each protein modifying the next in some way
signaling pathway
product manufacture and waste cleanup
breaks down proteins, the building blocks and mini-machines that make up many cell parts.
cell shape and inner organization
akin to a skeleton, and they compose structural elements in connective tissues like cartilage and bone in vertebrates
Ribosomes are responsible for synthesizing
proteins and rna
DNA STRUCTURE
DNA is made of two linked strands that wind around each other to resemble a twisted ladder, a shape known as a double helix.
Each strand has a backbone made of alternating sugar and phosphate groups. Attached to each sugar is one of four bases adenine (A), cytosine (C), guanine (G) or thymine (T).
Each base is held together
through hydrogen bonds
Adenine--->thymine
Sugar Phosphate Backbone
Each Sugar attaches to a base
each base contains nitrogen
part of DNA that stores information
joins together nucleotides in a DNA sequence
Cytosine--->Guanine
DNA FUNCTION
Structural
dependent on the sugar phosphate backbone and the bases.
forms the structural framework of nucleic acids, including DNA and RNA.
Deoxyribonucleicacid
DNA REAL TERM
Genetics
DNA holds genetic information that determines an organisms traits
These instructions are stored inside each of your cells, distributed among 46 long structures called chromosomes.
chromosomes are made up of thousands of shorter segments of DNA, called genes.
Immunological
DNA also contribute to the pathogenesis of autoinflammatory diseases and cancer.
DNA contains the instructions needed for an organism to develop, survive and reproduce.
DNA sequences must be converted into messages that can be used to produce proteins
DNA cannot function
without protein
and vise Versa
proteins provide structure and support for cells.
assist with the formation of new molecules by reading the genetic information stored in DNA.
transmit signals to coordinate biological processes between different cells, tissues, and organs
Carbohydrates
Sugars + Polymers of Sugars
Polysaccharides
Structure Polysaccharides
Cellulose
Made up of Beta glucose
Parallel chains held together through hydrogen bonds and form microfibrils.
Storage Polysaccharides
Starch
Plants
Amylopectin
Some branching
Amylose
Differ in structure
No Branching
Glycogen
Monosaccharides
Simplest Sugars
In aqueous solutions they form rings
Glucose
Beta Glucose
Undigestible because the OH group is at the top of the ring
Alpha Glucose
Digestable bc OH group is at the bottom
Made up of C, H, OH and CO groups
Aldoses
When the CO group is at the end of the chain the sugars
Ketoses
When CO group is in the middle of the chain there are called
Disaccharides
Formed when a dehydration reaction joins two monosaccharides
Serve as fuel and building material
Lipids
Cell
Prokaryotes
Lack membrane bound organelles, which are Rough ER, Golgi Apparatus, etc.
Cell Wall
Uniquely had peptidoglycon
Flagella
Movement
Fimbriae
Cell Membrane
Plasma membrane
No internal membrane bound organelles, whivh is what differs the most boldly of prokaryotes and eukaryotes, along with the absence of a nucleus
Lipids bilayer that surrounds the cytoplasm
Lipids have ester bonds that are created and join things together by dehydration reactions
Chromosome (DNA)
Nucleoid
Pili
Prokaryotic sex
Interact with other bacterial cells and are able to move strain of things around
Domain
Bacteria
No branching in the lipids in membrane
Cell wall
Presence of a cell wall
Presence of peptidoglycan in cell wall
Does not have membrane enclosed organelles
Archaea
Presence of branched lipids in membrane
Extremophiles
Halophiles
Can survive in highly salty environments
Thermophiles
Can survive in extreme temperatures
Methanogens
Have developed themselves to be able to survive in methane (usually in swamps)
They are strict obligate anaerobes
3 main domains of life
Eukarya
Does have a nucleus where the DNA are protected, in comparison to Bacteria and Archaea, where neither of them have a nucleus
Protists
Fungi
Plantaea
Anamalia
Capsules
Resistance to antibiotics
Polysaccharide layer that lies outside of the cell envelope
Ribosomes
Synthesis of protein
Autotroph
Phototroph
They are both energy sources for an autotroph, just in different ways depending on what the environment is
Needs LIGHT to survive
Chemotroph
Needs inorganic molecules to survive
NH3
Fe2+
Etc
Makes organic compounds out of inorganic molecules
Stanley-Millers Hypothesis/experiment
Based on the hypothesis that early life elements were being spouted from underwater volcanoes
The elements then became chemical compounds through chemical evolution
The compounds were put into a boiling water chamber to express the hot waters due to the volcanoes in early earth.
The that vapor was put into another chamber with electricity in it, symbolizing naturally occurring electricity through lightning
Organic compounds were the result of the experiment
C,H,O,N
Endospores
Helps the cell to survive harsh environments and can live in the cell for years
Four different kinds of Prokaryotes
Heterotroph
Photoheterotroph
Needs light to survive
Chemoheterotroph
Needs organic compounds to survive
Obligate Aerobes
NEEDS O2 to survive
Obligate Anaerobes
Cannot survive with O2, needs to not have it, O2 is toxic to it.
Energy source is fermentation
The chemical breakdown of a substance by bacteria, yeasts, or other microorganisms. They get their energy by breaking down something else, which in this case is oxygen gas. It needs to break down oxygen gas to feed itself, that's the only way it knows how to survive or CAN survive.
Facultative Anaerobes
Can survive with O2
Can survive without O2 by fermentation
Eukaryotes
Nucleus
nuclear envelope
double membrane enclosing nucleus
nucleolus
nonmembranous structure producing ribosomes
chromatin
DNA
proteins
nuclear membrane
nuclear membrane
progeria
a childhood disorder caused by point mutation. cells could die prematurely
cytoplasm
Plant Cell
vacuole
storage, breakdown waste, hydrolysis
food vacuole
when cells engulf food
contractile vacuole
pump excess water out
central vacuole
repository for inorganic ions
chloroplast
photosynthesis, converts sunlight into chemical energy
plasmodesmata
cytoplasmic channelsd that connect cytoplasms
cell wall
maintains cell's shapes and protects cell from damage
Animal Cell
Endoplasmic Reticulum
Rough ER
contains ribosomes
Smooth ER
doesn't contain ribosomes
Centrosome
where microtubules are initiated
cytoskeleton
microfilaments
cellular contraction
changes in cell shape
cytoplasmic streaming
intermediate filaments
formation of nuclear lamina
anchorage of nucleus + other organelles
microtubules
maintenance of chell shape
cell motility
chromosome movements in cell division
organelle movements
microvilli
increase cell surface area
lysosome
digestive organelle
phagocytosis
contains active hydrolytic enzymes, which digest food particles
autophagy
fuses with vesicle containing damaged organelles, which hydrolytic enzymes digest
storage disorder
inherited metabolic disorder and buildup of toxic materials in cells
peroxisome
metabolic function
mitochondria
cellular respiration and ATP
intermembrane space, outer membrane, inner membrane
golgi apparatus
synthesis, modification, sorting, secretion
ribosome
site of protein synthesis
endomembrane system
cilia
cell junction
tight junction
desmosomes
gap junction
They were the first cell ever created, where we started to get everything from
Chemical Bonds
Intramolecular
Covalent
Between two atoms. Electrons are shared bwteen atoms. Atoms with a higher electronegativity will pull electrons more therefore creating a polar molecule. When a molecule shares electrons equally, it is known as a nonpolar molecule.
Covalent bonds are seen in biology as glycosidic, peptide, ester, phosphodiester, disulfide bridge bonds.
Ionic
Between two fully charged ions. Giving and receiving electrons. Stronger as the charges are full.
Intermolecular Bonds
Nonpolar
Polar molecules
London Dispersion (1)
Every molecule has a set number of electrons. These electrons move randomly in an electron cloud. An instantaneous dipole movement occurs when electrons gather on one side of the molecule or atom. These instant dipole movements allow for instantaneous bonds. This bond is ALWAYS present but is the weakest out of the bonds listed. Most prominent between nonpolar molecules. Increases with surface area and amount of electrons in a molecule.
Dipole-dipole (2)
Hydrogen bond (3)
A type of dipole-dipole where a hydrogen is covalently bonded to a N, O, or F. This hydrogen is then intermolecularly bonded to any polar N, O, or F element of another molecule
Hydrogen bonds are incredibly important. They hold together proteins, DNA, enable water to be water, create functional groups, and regulate temperatures. They are a stronger form of dipole-dipole
Covalently bonded molecules that are polar have a dipole movement. The partially negative side of one molecule will bond with the partially positive side of another molecule. Stronger than london dispersion, but weaker than Ion-dipole.
Ion-dipole (4)
The strongest type of intermolecular bond. Seen commonly in dissolved solutions, such as salt water. Thus, salt water is more difficult to freeze and boil. This bond is between a fully charged ion and a partially charged side of a molecule. For instance, the negative Cl ion with the positive H´s in salt water.
Seen in the tiertiary structure of protiens.
Serve as fuel and building material
Water (H2O)
Water is made from a covalent bond of 2 hydrogens and 1 oxygen. Oxygen is much more electronegative than hydrogen, thus creating a strong dipole.
This means that water can hydrogen bond and is one of the most polar molecules. This means that water has a ton of awesome properties.
Universal Solvent
Water is the universal solvent because of its strong polarity and its relatively low molecular weight. Liquid water is everywhere.
Strong intermolecular bonds
Water has strong intermolecular bonds as a result of bring so polar. This allows for a high heat of vaporization and high specific heat. In turn, this helps to regulate temperatures so biology can exist the way it does.
Hydrolysis/dehydration
Water is extremely vital when it comes to forming and breaking ester bonds. These are seen in Lipids, carbohydrates, proteins, DNA, and basically everything.
Hydrophobic/hydrophilic interactions
Water-loving molecules exclude hydrophobic molecules such as lipids, which means that hydrophobic molecules stick together when in an aqueous environment. Amphiphilic molecules take advantage of the environment to surround hydrophobic molecules yet still flow with the surrounding water.
Flagella helps with movement by...
Fats
Fats: made up of a glycerol + 3 fatty acids
-Main function: energy storage
-Ester linkages are what connect each fatty acid to an OH in glycerol
Fatty Acids
Saturated
Saturated fats are solid at room temperature. There are no double covalent bonds between carbons because these molecules are saturated with hydrogen atoms at every position. They are also associated with an increase in cardiovascular disease.
Unsaturated
Unsaturated fats come from plant sources and are liquid at room temperature. These fats have one or more double covalent bonds that are found within the carbon chain. These molecules do NOT have hydrogen atoms at every position along the carbon chain.
Unsaturated Fatty Acids Isomers
Cis Isomers (same side): the presence of a double bond in cis causes the molecule to have a kink compared to the trans fatty acid.
Trans Isomers ( opposite side) AKA Transfats: the presence of a double bond with hydrogens on opposite sides.
Polyunsaturated Fats: more than one double bond
Monounsaturated Fats: one double bond
Steroids
Steroids are very different from fats in the way that they contain 4 fused rings
Also a precursor of other steroids including sex hormones
LDL
Low density lipoprotein or "bad cholesterol"
Found in animal and a common components of membranes
HDL
High density lipoprotein or "good cholesterol"
Phospholipids
Phospholipids: made up of a glycerol linked to 2 fatty acids (not 3)
- It contains a phosphate group on the head
- The phosphate group is polar
Phospholipid Head
Hydrophilic
Hearts water <3
Phospholipid Tail
Hydrophobic
Hates water : (